There are numerous situations in which it is necessary to precisely locate such people. In particular, in order to increase the safety of people in hazardous areas, there is a clearly expressed need for a system enabling rescue teams to provide rapid assistance to people in distress, such as:                people trapped beneath snow following an avalanche;        people who are unconscious following an accident in the mountains, for example a fall into a ravine, a crevasse, etc.;        survivors of a plane crash in an uninhabited area;        pleasure craft sailing close to coasts;        etc.        
Until now, the solutions used are based on radio transmitter/receiver type detection systems, which are manual systems, with a short range and used by a large number of people on the ground. Typically, a search and rescue team deployed to explore an avalanche zone comprises between twenty and fifty people using, in addition to the aforementioned manual systems, two or three metre long poles.
For example, for mountain rescue, the recognised systems are the “ARVAR 9000 Avalanche Beacon” (trademark) and the “RECCO” (trademark).
These recognised systems and methods have major drawbacks.
Firstly, because they have a short range, they do not provide an overall view of a search area.
Equally, because of their short range (60 metres in theory), they cannot be effectively used on board helicopters.
Moreover, they require a relatively large investment by those people who wish to protect themselves (for example, people in the mountains who could be caught in an avalanche).
Furthermore, such an investment only enables the person to be located by the given system, among a wide range of systems that are incompatible. It therefore appears difficult to require a person to invest in different equipment for various location systems.
The wide range of recognised location systems, and their incompatibility with each other, also poses a problem for the organisations that are responsible (for example, in France local councils in ski areas), being forced to choose a location system with the full knowledge that a low percentage of the population at risk is likely to benefit from it.
The invention has, in particular, the objective of abolishing or significantly reducing the various drawbacks of the current technology.
More precisely, one of the objectives of this invention is to provide a system for locating people that covers a much larger population than the current systems.
The invention also aims to provide a system that can locate simply, whatever the terrain in which the person to be located may be found.
Another objective of the invention is to provide a system that, in most cases, does not require any investment by the people who wish to protect themselves.
An additional objective of the invention is to provide a system that enables the number of people in a search and rescue team to be reduced.